AMC themselves have said that the show can last until 2019 or something like that, but like other shows such as Breaking Bad, they may cut the line soon.
Breaking Bad wasn't made to be a lasting show. Vince Gilligan said himself that the show was inevitably going to be cut short due to the nature of Walter's cancer.
As for the Walking Dead: Now that Andrea, Lori, Lizzie and Mika are dead, I can go on watching the show without yelling at my screen. Maybe if Maggie and Sasha carked it, it would make the show even more tolerable, but I'm really starting to hate the Casting Director for picking these actresses that give weak performances for such strong female characters.
I honestly get more emotion from the characters in the Telltale game than in the TV series.
P.S. Don't trust Bob Stookey